1. Field of the Invention
The present invention relates to an electronic chip holder which is employed for simultaneously handling a plurality of electronic component chips, and a method of forming electrodes on electronic component chips using the same.
Throughout the specification, the term "electronic component chips" includes electronic component chips in states of partially fabricated items which are not yet provided with external terminals, for example, in addition to those in states of finished products.
2. Description of the Background Art
FIG. 2 is a perspective view showing the appearance of a conventional electronic component chip holder 1. FIG. 3 is a sectional view showing a part of the holder 1 shown in FIG. 2 in an enlarged manner. Holders which are substantially identical in structure to this holder 1 are described in U.S. Pat. Nos. 4,381,321, 4,393,808, 4,395,184 and 4,526,129, for example.
The holder 1 is in the form of a plate as a whole, and is provided with a plurality of through holes 3 which are so sized as to receive a plurality of electronic component chips 2 one by one respectively and to hold the electronic component chips 2 received therein.
The body of the holder 1 is formed by an elastomer member 4, in which core members 5 of stainless steel, for example, are embedded in order to reinforce the same.
The electronic component chips 2 are ceramic capacitors, for example. The electronic component chips 2 are inserted in the respective through holes 3 of the holder 1 along the same direction, so that electrodes for serving as external terminals of such ceramic capacitors, for example, can be simultaneously formed on the plurality of electronic component chips 2. The sizes of the through holes 3 are designed to be smaller than sectional sizes of the electronic component chips 2, so that the electronic component chips 2 inserted therein can be held by elasticity of the elastomer member 4.
In general, rubber hardness of the elastomer member 4 is reduced or the sizes of the through holes 3 are increased, in order to prevent the electronic component chips 2 from chipping and cracking caused by an insertion pressure for inserting the same in the through holes 3.
Depending on the purpose of the holder 1, however, it may be necessary to considerably increase rubber hardness of the elastomer member 4 in order to improve heat resistance thereof, for example. The holder 1 must have high heat resistance when electrodes are formed on the electronic component chips 2 by dry plating, electrodes formed on the electronic component chips 2 are further coated with solder films, resin members coating the electronic component chips 2 are baked, and the like.
In such a holder 1 having the elastomer member 4 which is increased in rubber hardness, an insertion pressure for the electronic component chips 2 is apt to be increased and hence the electronic component chips 2 are often chipped or cracked. Although the sizes of the through holes 3 may be increased in order to reduce the insertion pressure, such increase is restricted. Thus, purpose of the holder 1 which is formed by the elastomer member 4 is limited.